Correct data size argument type in resource loading path to unsigned

Source/core/workers/WorkerScriptLoader.cpp

Index: Source/core/workers/WorkerScriptLoader.cpp
diff --git a/Source/core/workers/WorkerScriptLoader.cpp b/Source/core/workers/WorkerScriptLoader.cpp
index e8dd461fe72af707611c60422d1d6179801cefa5..e000aac6174b9017e60b5874126dbfa41243385b 100644
--- a/Source/core/workers/WorkerScriptLoader.cpp
+++ b/Source/core/workers/WorkerScriptLoader.cpp
@@ -122,7 +122,7 @@ void WorkerScriptLoader::didReceiveResponse(unsigned long identifier, const Reso
         m_client->didReceiveResponse(identifier, response);
 }
 
-void WorkerScriptLoader::didReceiveData(const char* data, int len)
+void WorkerScriptLoader::didReceiveData(const char* data, unsigned len)
 {
     if (m_failed)
         return;
@@ -137,9 +137,6 @@ void WorkerScriptLoader::didReceiveData(const char* data, int len)
     if (!len)
         return;
 
-    if (len == -1)
-        len = strlen(data);
-
     m_script.append(m_decoder->decode(data, len));
 }